code: def is_active(self):
      return self._i < len(self.creader)
  
file_path: whoosh/src/whoosh/query/qcolumns.py
imports: from whoosh.matching import ConstantScoreMatcher, NullMatcher, ReadTooFar
  from whoosh.query import Query
label_desc: Use image node_id 3 for calling the ColumnMatcher obj's underlying member method code with example usage: obj.is_active() and returns: unknown